Hitherto, films comprising a thermoplastic resin have been used as water-proof substrates of paper diapers, sanitary napkins or the like. However, in a case where thermoplastic resin films are used for the above mentioned water-proof substrates, there are some problems. In other words, such water-proof substrates give a cool touch to users' skin; are not cloth-like in appearance due to glistening, so that they do not look like high quality products; and do not have a good touch. In order to solve the above mentioned problems, that is, to provide a high quality cloth-like appearance, and soft and warm touch, various kinds of non-woven fabrics are laminated by adhering to a plastic film by the use of hot melt resin or the like. In order to laminate non-woven fabrics by the use of a hot melt resin, an apparatus for spraying a hot melt resin, a hot melt type adhesive comprising a low temperature melting resin that does not cause thermal damage to a film and a non-woven fabric are required, thus increasing the weight and the cost of the products. Moreover, a large area for adhering is required to ensure an excellent adhesion between a film and a non-woven fabric, so that it is difficult to apply hot melt resins as an adhesive agent inconspicuously and uniformly.
The object of the present invention is to solve the above mentioned problems and to provide a composite sheet comprising a non-woven fabric and a film (a laminated non-woven fabric sheet), which is suitable for a water-proof sheet of, for example, paper diapers or sanitary napkins, where a film and a non-woven fabric are adhered without using a specific adhesive such as a hot melt type adhesive or the like, so that the appearance is excellent, and a non-woven fabric and a film are easily and tightly bonded.